GB2462459A

GB2462459A - Variable width toaster

Info

Publication number: GB2462459A
Application number: GB0814473A
Authority: GB
Inventors: Nigel Wilkinson
Original assignee: Kenwood Ltd
Current assignee: Kenwood Ltd
Priority date: 2008-08-07
Filing date: 2008-08-07
Publication date: 2010-02-10
Also published as: GB0814473D0

Abstract

The invention relates to toasters especially, though not exclusively, intended for use in the domestic kitchen, and it relates in particular to such toasters having first and second toasting chambers of variable width to cope with foodstuffs of quite widely differing thickness, such as bread and bagels. Shown in side elevation, lever 20 may be moved in slot 22 to manually set the width of the first toasting chamber (20). The actuation of switch 28 controls the supply of power to heating elements 34 associated with the second chamber, thus the supply of power to heating elements 34 is disabled unless the lever 20 is set to the position associated with the minimum width of the first toasting chamber. An on0off selector switch may be provided using a non-contact, proximity reed switch and an electromagnetic actuator, the power to which can be switched on or off by the user, depending upon whether or not the second chamber is to be used.

Description

TOASTER

This invention relates to toasters, and it relates especially, though not exclusively, to toasters intended for use in the domestic kitchen.

Electrically operated toasters are stock items in most domestic kitchens, and they tend to be reasonably robust and reliable in use, despite the relatively modest purchase prices which have come to be established for them. Changes in traditional eating habits, however, leading to the development of popular taste for a wider variety of toastable foodstuffs, have recently led to technical developments which have increased the sophistication of toasters, enhancing their efficiency and providing greater flexibility of use.

One particular aspect of toasters which has received attention in this respect is their ability to cope with foodstuffs of quite widely differing dimensions; in particular, the thickness dimension of foodstuffs which users may wish to toast can vary quite widely. Several proposals have thus been made for so-called "variable-slot" toasters which can accommodate foodstuffs having width dimensions ranging from relatively narrow, say for thinly-sliced bread, to relatively wide, for bagels and similar products.

Our international patent application No. PCT/GB2006/002457 (Publication No. WO 2007/007038), based on GB 2427998 A, describes and claims a toaster with a toasting chamber of variable-width, and having in particular a toast-supporting carriage which is capable of adapting reliably to variations in the width of the toasting chamber and which is robust and reliable in use and economic to manufacture.

Toasters incorporating the aforesaid toast-supporting carriage are marketed by the applicants under the trade mark "Virtu" and have proven to be popular and highly functional.

The Virtu toasters currently have a single toasting chamber, accessed by a slot 14 in the upper surface 16 of the toaster 10, as shown in Figures 1(a) and 2 of the attached drawings, wherein Figure 1(a) shows the toaster 10 configured with its toasting chamber 12 (and associated slot opening 14) set at its minimum width, whereas Figure 2 shows the toaster configured with its toasting chamber 12 (and associated slot opening 14) set at its maximum width.

When the toasting chamber 12 (and associated slot opening 14) is set at its minimum width, as shown in Figure 1, the unused part of the toasting chamber is closed off by a cover 18. The width of the chamber 12 is manually adjustable by means of a lever 20 which runs in its own slot 22, running fore-and-aft of the toaster, and which is coupled to a mobile wall 24 of the chamber 12.

It is an object of this invention to increase the utility of the toaster by rendering usable the unused part of the toasting chamber, and to provide apparatus and means whereby such increased utility is provided.

According to the invention there is provided a toaster having first and second toasting chambers arranged side by side, each chamber being provided with its own heating means; wherein the first toasting chamber is variable in width and manually settable to a plurality of settings between a minimum width dimension and a maximum width dimension; the heating means for the second chamber being inhibited unless the said first chamber is set at or near its minimum width dimension.

In preferred embodiments, the means for manually setting the width of said first toasting chamber comprises a lever member movable along a slot between first and second extreme positions, associated respectively with said maximum and minimum width dimensions.

In such embodiments, it is further preferred that an operating member formed as part of, or otherwise associated with, said lever member is provided with means configured and dimensioned to actuate a switch member when said lever member nears its second extreme position.

Preferably, said switch member comprises part of an energisation circuit for the heating means for said second chamber.

In one preferred embodiment, the switch member comprises a mechanically actuated switch having normally open contacts; said switch further having a casing, and a plunger normally urged outwardly of said casing by resilient means; said contacts being closed when said actuator means contacts said plunger with sufficient force to move said plunger against the urge provided by said resilient means.

In another preferred embodiment, said switch member comprises a magnetically operated reed switch and said actuator member comprises a magnetic member.

In some preferred embodiments, the first and second toasting chambers share a common, mobile wall configured to support components of the heating means for both chambers.

In such embodiments, the said common wall may comprise an electrically insulating support member supporting respective heating elements for the first and second toasting chambers.

Further preferably, the elements may be supported on a substantially planar and rectangular support member, for example of mica; one element being wound between connection points spaced apart along the upper and lower edges of the support member and the other being wound between connection points spaced apart along the upright edges of the support member.

Conveniently, in any of the foregoing embodiments, at last said first toasting chamber includes a food-supporting carriage comprising respective elongate members mounted to either side of the toasting chamber and linked together by linking members which form part of the food-supporting surface and are pivotally attached to the elongate members to accommodate lateral relative movement between the elongate members as the width of the said toasting chamber is varied.

In some such embodiments, it is preferred that unitary linking members link the two elongate members and the elongate members are urged apart by a spring. In other such embodiments, the linking members comprise a plurality of chevron-like links distributed along the length of the elongate members and having pivots at the chevron points permitting the chevron angle to vary with variations in the width-dimension of the chamber.

The chevron-like links may be regularly distributed along the length of the elongate members, and the elongate members may be notched to receive the chevron point pivots when the chamber is adjusted to its narrowest width dimension.

In another preferred embodiment, the control means includes resilient means acting upon at least one of said linking members for urging said elongate members apart.

In one such preferred embodiment, the resilient means comprises a coil spring, configured to operate in either compression or tension, fixedly supported upon one of said elongate members and connected to at least one of said linking members. By this means, the necessary resilient urge is applied in a simple and cost-effective manner.

In another preferred embodiment, the resilient means comprises a torsion spring; the shape and dimensions of which may, in some configurations, prove more convenient or more compact in use than a coil spring.

In other preferred embodiments, the resilient urge is provided by plural spring members carried by one of said elongate members; each of said spring members being coupled between a respective fixed location on said elongate means and a respective one of said linking members. It is further preferred that said spring members are evenly distributed among said linking members. In such circumstances, coil springs or torsion springs, or a combination of both, may be used.

It is further preferred that pivotal mounting points for the linking members are regularly distributed along the elongate members, thereby providing an even distribution of the resilient urging force.

In order that the invention may be clearly understood and readily carried into effect, embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figures 1(a) and 2 have already been referred to; Figure 1(b) shows the toaster of Figure 1(a), temporarily configured as a two-chamber toaster in accordance with one example of the present invention; Figure 3 shows in schematic form an arrangement whereby the heating elements for the second toasting chamber are disabled unless the width of the first slot is set at or near its minimum dimension; and Figure 4 shows, in schematic outline, a dual-element assembly supported on a common wall member, and thereby comprising one heating element for each chamber.

Referring now in general to Figure 1(b) and in detail to Figure 3, the lever 20 is shown in side elevation, mobile to and fro along the slot 22 to permit the width of a first toasting chamber 12 to be manually set by a user. The lever may be freely movable to provide so-called infinite adjustment, or it may be settable at a number of discrete positions along the slot. In any event, in this embodiment, the lever 20 carries a mechanical actuator member 26, which preferably comprises a pad of firm, but resilient material capable of absorbing mechanical shock, at least to a degree. The actuator member 26 is sited so as to physically engage and operate the plunger 28a of a microswitch 28, firmly mounted by any convenient means to the chassis of the toaster 10. The plunger of the microswitch 28 is resiliently urged to an open position, in which the plunger protrudes from the body of the microswitch, and is urged into its closed position when the actuator 26 engages the plunger sufficiently firmly to overcome the resilient urge applied to the plunger. The resilience of the pad comprising actuator member 26 is designed to protect the microswitch in the event that the lever 20 is moved towards the minimum-width setting position with undue force.

The actuation of switch 28 into its closed position applies a low voltage signal to a controller 30 which is configured to enable a router 32 which controls the supply of electrical power to heating elements 34 associated with the second toasting chamber. Thus the supply of power to the heating elements 34 associated with the second heating chamber is disabled unless the lever 20 is set to the position associated with minimum width of the first toasting chamber.

It will be appreciated that the elements 34 could be energised when the toasting chamber is near, rather than at, its minimum width setting, merely by changing the thickness of the pad comprising actuator 26.

It will further be appreciated that the microswitch and pad actuator could, if desired, be replaced by a non-contact proximity switch, such as a reed switch, and a magnetic actuator.

Naturally, the elements 34 will not need to be energised each time the lever 20 is moved to the minimum width setting for the first toasting chamber, and thus an individual set of the standard toaster controls, or at least an on-off selector switch, may be provided for the second toasting chamber; this switch being settable by a user of the toaster so as to enable power to be supplied to the elements 34 only if the user wants to utilise the second chamber for toasting.

In one such embodiment, a convenient on-off selector switch is provided by using a non-contact, proximity reed switch and an electro-magnetic actuator, the power to which can be switched on or off by the user, depending upon whether or not the second chamber is to be used.

In circumstances where power is enabled (by the combination of the setting position of the lever 20 and user-actuation of the selector switch) to flow to the elements 34 of the second toasting chamber, the toasting operation within that chamber may be controlled either in common with settings chosen for the first chamber 12 by user-actuation of standard controls such as those shown at 36 and 38 in Figures 1 and 2, or individually by way of a second set of such controls (not shown).

The position of the mobile common wall 24 between the two toasting chambers is adjustable by means of the lever 20, as has been described, and it is desirable that this common wall is configured to support a respective electrical heating element for each of the toasting chambers.

Conveniently, the common wall 24 consists of or includes a rectangular, plate-like supporting member of electrically and thermally insulating material, such as mica, supporting respective heating elements for the first and second toasting chambers. It is then preferred that one element is wound between connection points spaced apart along the upper and lower edges of the support member and the other element is wound between connection points spaced apart along the upright edges of the support member, as schematically shown in Figure 4, wherein the supporting member is shown at 40 and the respective heating elements at 42 and 44. The heating elements are tape-like resistance elements of well-known kind; those of element 42 being wound between upper and lower arrays 46 and 48 of connection points distributed regularly along the upper and lower edges of the member 40 and those of element 44 being wound between arrays 50 and 52 of connection points distributed regularly along the vertically disposed edges of the member 40.

The arrays 46, 48, 50 and 52 of connection points are not necessarily distributed regularly along the edges of the support member 40, as described above. Indeed, in some circumstances, it may be preferred to use non-regular spacings in some or all of the arrays to achieve a desired heating pattern for the elements as a whole. It will be understood by those skilled in the art that the number of connection points shown in the arrays 46 to 52 is not representative of the number that would be used in practice, where a significantly greater number of connection points would be used. Figure 4 is intended merely to conceptually illustrate how tape-wound heating elements could be arranged on a common wall or support member.

If desired, thermal insulation between the two toasting chambers can be improved by incorporating a thermally reflective interlayer into the support member 40.

Claims

CLAIMS: 1. A toaster having first and second toasting chambers arranged side by side, each chamber being provided with its own heating means; wherein the first toasting chamber is variable in width and manually settable to a plurality of settings between a minimum width dimension and a maximum width dimension; the heating means for the second chamber being inhibited unless the said first chamber is set at or near its minimum width dimension.
2. A toaster according to claim 1, wherein the means for manually setting the width of said first toasting chamber comprises a lever member movable along a slot between first and second extreme positions, associated respectively with said maximum and minimum width dimensions.
3. A toaster according to claim 2, wherein an operating member formed as part of, or otherwise associated with, said lever member is provided with actuator means configured and dimensioned to actuate a switch member when said lever member nears its second extreme position.
4. A toaster according to claim 3, wherein said switch member comprises part of an energisation circuit for the heating means for said second chamber.
5. A toaster according to claim 3 or claim 4, wherein said switch member comprises a mechanically actuated switch having normally open contacts; said switch further having a casing, and a plunger normally urged outwardly of said casing by resilient means; said contacts being closed when said actuator means contacts said plunger with sufficient force to move said plunger against the urge provided by said resilient means.
6. A toaster according to claim 3 or claim 4, wherein said switch member comprises a magnetically operated reed switch and said actuator member comprises a magnetic member.
7. A toaster according to any preceding claim, wherein the first and second toasting chambers share a common, mobile wall configured to support components of the heating means for both chambers.
8. A toaster according to claim 7, wherein the said common wall may comprise an electrically insulating support member supporting respective heating elements for the first and second toasting chambers.
9. A toaster according to claim 8, wherein the elements are supported on a substantially planar and rectangular support member, for example of mica.
10. A toaster according to claim 8 or claim 9, wherein one element is wound between connection points spaced apart along the upper and lower edges of the support member and the other is wound between connection points spaced apart along the upright edges of the support member.
11. A toaster according to any precding claim, wherein at least said first toasting chamber includes a food-supporting carriage comprising respective elongate members mounted to either side of the toasting chamber and linked together by linking members which form part of the food-supporting surface and are pivotally attached to the elongate members to accommodate lateral relative movement between the elongate members as the width of the said toasting chamber is varied.
12. A toaster according to claim 11, wherein unitary linking members link the two elongate members and the elongate members are urged apart by a spring.
13. A toaster according to claim 11, wherein the linking members comprise a plurality of chevron-like links distributed along the length of the elongate members and having pivots at the chevron points permitting the chevron angle to vary with variations in the width-dimension of the chamber.
14. A toaster according to claim 13, wherein the chevron-like links are regularly distributed along the length of the elongate members, and the elongate members are notched to receive the chevron point pivots when the chamber is adjusted to its narrowest width dimension.
15. A toaster according to any of claims 11 to 14, wherein the control means includes resilient means acting upon at least one of said linking members for urging said elongate members apart.
16. A toaster according to claim 15, wherein the resilient means comprises a coil spring, configured to operate in either compression or tension, fixedly supported upon one of said elongate members and connected to at least one of said linking members.
17. A toaster according to claim 15, wherein the resilient means comprises a torsion spring.
18. A toaster according to any of claims 15 to 17, wherein the resilient means comprises plural spring members carried by one of said elongate members; each of said spring members being coupled between a respective fixed location on said elongate means and a respective one of said linking members.
19. A toaster according to claim 18, wherein said spring members are evenly distributed among said linking members.
20. A toaster according to claim 19, wherein pivotal mounting points for the linking members are regularly distributed along the elongate members, thereby providing an even distribution of the resilient urging force.
21. A toaster substantially as herein described.